The invention relates to a method of manufacturing a magnetic device comprising at least one thin domain layer of a magnetizable material which has an easy axis of magnetisation which is substantially normal to the surface of the layer, a detection pattern of magnetoresistive material and a propagation pattern of magnetizable material being provided on said layer, the method comprising the step of providing a nonmagnetic substrate body with at least one thin layer of a magnetizable material and the step of providing said layer of magnetizable material, by means of mask technology, with the propagation pattern of magnetizable material and with the detection pattern of magnetoresistive material.
Such a method is known from AIP Conference Proceedings No. 24 Magnetism and Magnetic Materials 1974 pp. 556-557. The magnetic device is used for propagating and detecting magnetic domains. The configuration of the pattern of magnetizable material is such that the magnetic domains are propagated by means of a magnetic field. For this purpose, the configuration satisfies that of a propagation element for magnetic domains. The configuration of the pattern of magnetoresistive material is such that the magnetic domains are detected by means of an electric current. For this latter purpose the configuration satisfies that of a detection element for magnetic domains. In the method the layer of magnetizable material is covered with an SiO.sub.2 layer by sputtering. Vapor deposited on said SiO.sub.2 layer is a permalloy film on which a propagation structure of permalloy is provided by means of a first mask. This is the pattern of magnetizable material. Parts of the permalloy film are then removed by means of a second mask by means of sputter-etching, such that the detection pattern of magnetoresistive material remains. In this method the second mask has to be aligned very accurately with respect to the pattern of magnetizable material already present. It is stated in the article that as a result of this alignment requirement in the manufacture of the device the size of the domains is restricted to not less than a diameter of 1 .mu.m.